1 The Non-Boussinesq ROMS and Its Applications Y. Tony Song Jet Propulsion Laboratory Contents: 1.The development of non-Boussinesq ROMS (Hou, Caltech; Colberg, JPL) 2.GRACE, inter-ocean transport (Zlotnicki, JPL; Susanto, Lamont-Doherty) 3.Coupled earthquake-ROMS for tsunami prediction (Caltech & OSU)

2 Grace Ocean Bottom Pressure TOPEX/Poseidon Sea Surface Height Stratified Ocean Launched 2002 T/P-Jason provides SSH, representing volume changes (heat expansion), but most ocean models are incompressible. GRACE measures ocean bottom pressure, representing water mass changes, but most models are not mass-conserving or topography-following. Observing Ocean’s Surface & Bottom

3 ROMS vs non-Boussineq ROMS Tony Song, January 2006 SCRUM/ROMSROMS 1. S-coordinate (Song&Haidvogel 1994): 2. Sp-coordinate (Song&Hou 2006; Song et al. 2005): Ocean-bottom-pressure model (non-Boussinesq ROMS)

4 Non-Boussinesq Global Ocean Model Results SOI (E---W): Atmospheric pressure Oscillation Nino3 (E---W): SST Oscillation The strongest OBP signal in the northern hemisphere

5 Tony Song, August 2006 GRACE-Observed Ocean Mass Changes Sumatra earthquakes Greenland ice melting fast than previous thought

6 Focusing on the North Pacific

7 Tony Song, October 2007 ROMS_NB Development List: based on recent ROMS couple sea-ice couple earthquakes couple land loading See Frank Colberg’s poster

8 JGR-Ocean special section (111, 2006): Dynamic Processes and Circulation in Yellow Sea, East China Sea, and South China Sea Tony Song, August 2004 Guest editors: Zheng (UM), Fang (FIO) & Song (JPL) List of Papers for JGR Special Issue 1.Sea surface temperature variability in the China Seas from 1982 to Observations of coastal upwelling in summer 2000 in the northeastern South China Sea 3.Current measurements and spectral analyses in the Luzon Strait during spring of Thermohaline circulation in the Deep South China Sea Basin inferred from oxygen distributions 5.Measurements of the turbulent energy dissipation rate ε and an evaluation of the dispersion process of the Changjiang Diluted Water in the East China Sea 6.Numerical simulation of meandering, patch and lens structures of Changjiang Diluted Water in Yellow Sea 7.Analyses of Upper Layer Thickness Variation in the South China Sea from Satellite Altimeter Data and In-situ Measurements 8.Estimate Interbasin Transport Using Ocean Bottom Pressure. Part I: Theory and Model for Asian Marginal Seas 9.Regional Wind and the Lombok Strait Throughflow 10.Three-dimensional structure of the summertime circulation in the Yellow Sea from a wave-tide- circulation coupled model 11.Interannual variability of the gap in the Indo-Pacific warm pool over South China Sea associated with ENSO and IOD 12.Acoustic transmission in the cold eddy in the southern East China Sea 13.Surface current field and seasonal variability of Kuroshio and adjacent regions derived from satellite- tracked drifter data 14.Development of Sub-surface Warm Water in East China Sea in Fall 15.Variation of the Yellow Sea Warm Current and related eddies in winter 16.Observation of the seasonal evolution of the Yellow Sea Cold Water Mass in 1996 – The mechanism of internal waves in the Luzon strait 18.The development of ocean and ecosystem numerical models and applications to the Southern Yellow Sea 19.Current structures and their seasonal variation in Huanghai (Yellow) Sea and East China Sea 20.Response of the South China Sea circulation to El Nino as seen from the variable-grid global ocean model results 21.The upwelling off Yangtze River estuary and adjacent sea in summer 22.Interannual variation of the South China Sea surface fields in the recent decade from satellite observations 23.The upwelling system in the Yellow Sea and East China Sea: Results from Field Observations and Numerical Modeling 24.The current-vortex structure of the Southern East China Sea in Summer 25.Winter Fronts in Taiwan Strait 26.Origin and distribution patterns of Sediments in the Southern Yellow Sea 27.A numerical study on dynamic mechanisms of seasonal temperature variability in the Yellow Sea 28.The characteristics of hydrographic and chemical elements of the Yellow Sea and East China Sea in summer, 1998

9 Asian Marginal Seas & Their Connections Tony Song, August 2004 Inter-basin transport is difficult to estimate because of its: complex geometry dependence on local and remote forcing (a) (b) (d) (c) (Song, JGR-Oceans, 2006)

10 Geostrophic and Hydraulic Control Tony Song, August 2004 (b) Whitehead [1989] gives a simple method to estimate the mean transport (upper bound) by hydraulic control theory. (a) Garret & Toulany [1982] gives a simple method to estimate the surface geostrophic transport. Estimate strait transport by Combining (a) and (b):

11 Seasonal Variability  Ocean Bottom pressure is necessary for a better estimate of the seasonal inter-basin transports Tony Song, August 2004 Based on SSH onlyBased on SSH and OBP

12 Coupled Earthquake-Ocean Model for Tsunami Study Tony Song, January 2006 Related Work Song et al., The 26 December 2004 tsunami source estimated from satellite radar altimetry and seismic waves, GRL, 32, doi: /2005GL (2005). Song et al., Horizontal impulses of continental slopes dictate the 26 December tsunami, revised for Ocean Modelling (2007) Song, Y.T., Detecting tsunami genesis and scales directly from coastal GPS stations, GRL, 34, doi: /2007GL (2007). Song and Han: Satellite observations challenging the long-held tsunami genesis theory, Review in Nature (2007).

13 Tsunami and Earthquake History Zhang Heng ( 張衡, 78 – 139 A.D.) was an astronomer, mathematician, inventor, and poet of the Eastern Han Dynasty in ancient China astronomermathematicianinventorEastern Han Dynasty China Famous for his invention of the first seismograph (132 A.D.) Thucydides (460 – 400 B.C.) was a Greek historian of the Peloponnesian War. Recorded the Aegean Sea tsunami (426 B.C.) Seismometers can detect only earthquakes, but not a tsunami itself, which is dangerous to many coastal communities. When earthquake is coupled with ocean models on modern computers, they are able to provide early warnings for those coastal regions at risk.

14 Tony Song, January 2005 More recent tsunamis: No successful warning so far. DateLocationMagnitudeEarly Warning?Fatalities 26 Dec Mar 2005 Sumatra Nias Island no yes 230,000 Panic evacuation (~100) 19 July 2006West Java7.7no~600 June 2005 May 2006 Nov 2006 Jan 2007 Mar 2007 California Tonga North Japan Solomon Is yes Yes ? False alarm False Alarm ~30 Since 1982, tsunami warnings based on earthquake magnitude have produced false alarms 16 out of 16 in Pacific (U.S. Government Accountability Office, GAO ). State of Hawaii’s estimation: an evacuation from a tsunami alarm in 1996 would have cost the state $58.2 million in economic losses. 1. Introduction

15 2. Tsunami Prediction System seafloor motions Predict Tsunami Tony Song, January 2006

16 Tony Song, January Tsunami Genesis Theory Song et al. (2007): deriving tsunami-source energy directly from ground motions. Conclusion 1: Earthquake energy ≠ Tsunami energy Conclusion 2: Lateral motions of continental slopes transfer the major tsunami energy

17 4. GPS-Predicted Tsunamis Directly detect the mechanism that generates tsunamis. By-passing the earthquake- magnitude- based method that had often caused false alarms. Tony Song, January 2006 (validated by three historical events)

18 5. Determine Tsunami Scales Earthquakes—Richter’s scale (magnitude) Hurricanes—Simpson’s scale (category) Tsunamis can be scaled ( based on sqrt (E T ) ~ tsunami height ): 1.If S T < 5, local warning only. 2.If S T > 5, basin-wide warnings and modeling are needed. 3.Early warnings can be issued in 20 minutes after quake. Tony Song, January 2006 Earthquake MagnitudeTsunami Energy (E T ) Tsunami Scale (S T ) Basin-wide Warning? GPSSeismicGPSSeismicS T = 5 threshold 2004 Sumatra (M w 9.2)6.0e+15 J5.2e+15 J5.85.7>> 5 Yes 1964 Alaska (M w 9.2)8.2e+15 J5.9>> 5 Yes 2005 Nias (M w 8.7)2.8e+14 J2.2e+14 J4.44.3<< 5 No

19 6. Validations (1964 & 2005 Tsunamis) Tony Song, January 2006

20 7. Proposed tsunami-detection Plan Plan3. GPS detection system (~$5 millions) serves two purposes: 1.Detect tsunami potentials 2.Monitor plate boundaries Plan2. DART buoys: ~$50 millions Pacific only (does not protect people on the coastal side) Plan1. Satellite-constellations: ~$300 millions (Nobody wands to pay for it) Tony Song, January ,440 GPS stations

21 At United Nations Description of Event: JPL’s tsunami prediction concept was selected and reported at UN’s EWC3, Mach 25~30, 2006, Bonn, Germany German newspaper report: “Tension at the border” …Tony Song of NASA broke silence on Tuesday at the international early warning conference in Bonn. Before the event, former US president Bill Clinton and Federal Minister of Foreign Affairs Frank-Walter stone Meier and more than 1000 scientists urged to furnish as fast as possible warning systems for Tsunamis. But now Song demonstrated his colleague that they had not understood the cause of the giant waves correctly. According to the established theory a Tsunami develops, if the sea water gets an impact with a sea-quake transferred by the sea- bottom: The soil moves thereby like a piston perpendicularly upward, it is said. Song meanwhile found out that the Tsunamis was released on 26 December 2004 particularly when lateral breaking the soil….

22 Summary Tony Song, January 2006 The development of non-Boussinesq ROMS has several important applications: Mass-related ocean climate studies Geodedic-related applications (earth rotation, GPS, tsunami) Hydrological applications (ice, land fluxes) All of these topics are relevant to NASA’s missions.